Category Archives: Science

New paper – Measuring Mental Time Travel in Animals

For pdf click here: Williams – Measuring Mental Time Travel In Animals

Hasok Chang describes in Inventing Temperature how scientists dealt with the problem of measurement verification circularity when standardizing the first thermometers ever constructed. The problem can be illustrated by imagining you are the first scientist who wanted to measure the temperature of boiling water. What materials should you use to construct the measuring instrument? Once built, how do you verify your thermometer is measuring what you claim it is without circularly relying on your thermometer? Appealing to more experimentation is unhelpful because we must use a thermometer to carry out these experiments, and thermometers are what we are trying to determine the reliability of in the first place. Hasok Chang calls this the Problem of Nomic Measurement (PNM), which is defined as:

The problem of circularity in attempting to justify a measurement method that relies on an empirical law that connects the quantity to be measured with another quantity that is (more) directly observable.1 The verification of the law would require the knowledge of various values of the quantity to be measured, which one cannot reliably obtain without confidence in the method of measurement.

Stated more precisely, the PNM goes as follows:

1. We want to measure unknown quantity X.

2. Quantity X is not directly observable, so we infer it from another quantity Y, which is directly observable.

3. For this inference we need a law that expresses X as a function of Y, as follows:X = f(Y).

4. The form of this function f cannot be discovered or tested empirically because that would involve knowing the values of both Y and X, and X is the unknown variable that we are trying to measure.

My aim for this paper is to apply the PNM to an on-going debate in cross-comparative psychology about whether and to what extent non-human animals can “mentally time travel”. In 1997, Suddendorf and Corballis argued “the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals”.2 In 2002, Roberts argued non-human animals are “stuck-in-time”. Since then, a number of psychologists have defended similar claims. Endel Tulving states this hypothesis clearly:

There is no evidence that any nonhuman animals—including what we might call higher animals—ever think about what we could call subjective time…they do not seem to have the same kind of ability humans do to travel back in time in their own minds, probably because they do not need to. (Tulving, 2002, p. 2)

Call the claim that mental time travel is unique to humans Uniqueness. Naturally, Uniqueness has not gone unchallenged. One worry is that different theoretical assumptions about what counts as “mental time travel” are leading to disagreements over whether animals do or do not possess MTT. Furthermore, both sides of the debate more or less agree about the behavioral evidence, but disagree about how to interpret the evidence qua evidence for or against Uniqueness. This raises a problem of verification circularity similar to the PNM:

1. We want to measure MTT in animals

2. MTT is not directly observable, so we infer it from behavior Y, which is directly observable.

3. For this to work, we need to know how to infer MTT from behavior alone.

4. The form of this function cannot be discovered or tested empirically because that would involve knowing the unknown variable we are trying to measure (MTT).

Accordingly, my central thesis is that the question of whether animals can mentally time travel is not a purely empirical question. My argument hinges on premise (3): if psychologists have irreconcilable differences in opinion about which behaviors best express MTT, they will use the construct “mental time travel” to describe distinct phenomena and thus make different inferences from behavior to MTT. For example, if defenders of Uniqueness are using MTT as a label to describe a human autapomorphy3 but critics of Uniqueness are using MTT as a label for a core capacity shared with other animals, then they are clearly talking past each other and the debate is reduced to a semantic dispute about whether the term “MTT” is applied to “core” capacities or uniquely human traits.4 Therefore, I argue the empirical question of whether animals can in fact mentally time travel is intractable unless theorists can agree on both the connotative and denotative definitions of the term i.e. approximate agreement on the conceptual definition as well as agreement on its conditions of realization in the physical, measurable world.

1Chang does not analytically define the notion of “direct observation” but the paradigm case is observing the read-out of an instrument e.g. writing down the height of a column of mercury in a glass tube. Chang defends a hybrid version of foundationalism and coherentism whereby we begin scientific inquiry with some tentatively held beliefs justified by experience, especially the belief that we are capable of accurately observing the read-outs of our instruments.

2Citing neurological overlaps between “episodic-like” memory in non-human animals and human episodic memory, Corballis has recently dissented (2012). In his (2011) book, Corballis argues that what makes humans unique is our capacity for MTT and symbolic language super-charged by the capacity for recursivity i.e. Alice believes Bob desires that Chris thinks highly of Bob’s desire for Alice. Another recent convert is Roberts (2007), taking back his (2002) claims about MTT in animals.

3An autapomorphy is a derived trait that is unique to a terminal branch of a clade and not shared by other any members of the clade, including their closest relatives with whom they share a common ancestor.

4“We caution against grounding the concept of episodic-like memory in the phenomenology of the modern mind, rather than in terms of core cognitive capacities.” (Clayton et al 2003, p. 437)

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Quote for the Day – Einstein’s Louse and the Limits of Scientific Understanding

Nature is showing us only the tail of the lion, but I have no doubt that the lion belongs to it even though, because of its large size, it cannot totally reveal itself all at once. We can see it only the way a louse that is sitting on it would.

 ~Albert Einstein to Heinrich Zangger, quoted in Clifford Pickover, Archimedes to Hawking


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Quote for the Day – Newton the Magician

“Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind which looked out on the world with the same eyes as those who began to build our intellectual inheritance rather less than ten thousand years ago…[Newton saw] the whole universe and all that is in it as a riddle, as a secret which could be read by applying pure thought to certain evidence, certain mystic clues which God had laid about the world to allow a sort of philosopher’s treasure hunt…He regarded the universe as a cryptogram set by the Almighty…”

~ John Maynard Keynes, ‘Newton, the Man”, quoted in Clifford Pickover, Archimedes to Hawking

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Book notice: Stephen J. Gould’s The Panda’s Thumb

A used copy of Stephen J. Gould’s book The Panda’s Thumb (1980) has been sitting on my shelf for a while, and I’m kicking myself for not reading it sooner. What a delightful little book of science essays! Each essay is an edited version of one of his monthly columns at Natural History magazine. Subsequently, the essays are intelligible to the general intelligent reader, but Gould does not thereby sacrifice an appreciation for hard facts and subtle reasoning. Gould makes science come alive with his anecdotes, wry humor, and gentle argumentation about topics ranging from the panda’s thumb to hopeful monsters and everything in between. Nothing is too big or small for Gould to think worthy of writing about. All in all, I highly recommend this book for any student of biology or lover of science.

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Quote for the Day – The Hunch That Killed Pluto

By now it seemed to me inevitable that, whether anyone realized it or not, astronomers were on an unstoppable march that would eventually lead to a tenth planet. It seemed to me obvious that it was there, slowly circling the sun, just waiting for the moment when someone somewhere pointed a telescope at the right spot, noticed something that hadn’t been there earlier, and suddenly announced to an unsuspecting world that our solar system had more than nine planets.

Sitting beneath the massive Hale Telescope that foggy night, ever the scientist, Sabine asked, “What evidence do you have?”

I told her about all of the recent astronomical discoveries. But when pressed for evidence, I had to admit: I had none whatsoever. I had a hunch. Officially, scientists don’t work on hunches. We work on hypotheses and observations and plenty of evidence. Hunches don’t get you research funding, tenure at your university, or access to the world’s largest telescopes. But a hunch was all I had. No one had systematically looked across the sky for a new planet since the 1930s, when Pluto itself was found, and even though astronomers knew of almost five hundred bodies in the Kuiper belt, the searches had been, of necessity, piecemeal, and no one had yet mounted a careful search like the one that had uncovered Pluto. Now, seventy years after the discovery of Pluto, telescopes were bigger and better, computers made searches vastly more powerful, and astronomers simply knew more about what they were looking for. How could it be that if someone went and looked again for a new planet they wouldn’t find something that had been just beyond the reach of the telescopes in the 1930s? There had to be a tenth planet. The possibility that Pluto was a unique planetary oddball out at the edge of the solar system seemed absurd to me.

~Mike Brown, How I Killed Pluto and Why It Had It Coming

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Quote for the Day – Is Evolutionary Biology Inherently Sexist? No, says Sarah Hrdy

Evolutionary biology, and its offspring, sociobiology, are not inherently sexist. The proportion of “sexists” among their proponents is probably no greater than the proportion among scientists generally. To be sure, contemporary analyses of mammalian breeding systems can cause even a committed Darwinian like myself to contemplate her gender with foreboding. Yet, it is all too easy to forget, while quaking, that sociobiology, if read as a prescription for life rather than a description of the way some creatures behave, makes it seem bad luck to be born either sex.

~Sarah Blaffer Hrdy, The Woman That Never Evolved, p. 14

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Quote for the Day – Evolutionary Biology, Social Darwinism, and Feminism

Social Darwinism has, almost indelibly, tainted most people’s understanding of evolutionary theory-certainly as it applies to human beings. Yet social Darwinism differs from Darwinism-without-adjectives in one all-important way, and ignoring this distinction has been one of the most unfortunate and long-lived mistakes of science journalism. Darwinism proper is devoted to analyzing all the diverse forms of life according to the theory of natural selection. Darwinists describe competition between unequal individuals, but they place no value judgment on either the competition or its outcome. Natural-selection theory provides a powerful way to understand the subordination of one individual, or group of individuals, by another, but it in no way attempts to condone (or condemn) subordination.

By contrast, social Darwinists attempt to justify social inequality. Social Darwinism explicitly assumes that competition leads to “improvement” of the species; the mechanism of improvement is the unequal survival of individuals and their offspring. Applying this theory to the human condition, social Darwinists hold that those individuals who win the competition, who survive and thrive, must necessarily be the “best.” Social inequalities between the sexes, or between classes or races, represent the operation of natural selection and therefore should not be tampered with, since such tampering would impede the progress of the species. It is this latter brand of Darwinism that became popularly associated with evolutionary biology. The association is incorrect, but it helps to explain why feminists have steadfastly resisted biological perspectives.

~Sarah Blaffer Hrdy, The Woman That Never Evolved, p. 12-13

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